1. Field of the Invention
The present invention relates to electrical electric generators and, more specifically, to a hybrid generator that generates electrical energy from both mechanical energy and chemical energy.
2. Description of the Related Art
The ever increasing energy demand of modern society is perhaps among the greatest challenges humankind is and will continue to face. Research in energy includes such areas as: mega-scale energy conversion, renewable and green energy, efficient energy transmission, energy storage, energy harvesting, and sustainable power source for micro-nano-systems. In addition to large-scale energy harvesting from ‘renewable’ sources such as wind, hydro, and solar, there is also significant opportunity to harvest the wasted energy in our personal environments, such as from walking, typing, speaking and breathing. If efficiently harvested to its full potential, many of the modern energy requirements needed for small devices and even personal electronics could be fulfilled. This is a new trend in the worldwide effort in developing technologies related to energy scavenging.
Energy harvested from the environment may be sufficient for powering nanodevices used for periodic operation, owing to their extremely low power consumption and small sizes. For example, certain devices can all be foreseen as potential applications that need implantable energy sources, examples include: an implantable device that wirelessly communicates the local glucose concentration for diabetes management; or the local temperature for infection monitoring after surgery; or a pressure difference to indicate blockage of fluid flow in the central nervous system and/or blood clotting. Powering such devices could be accomplished by concurrently harvesting energy from multiple sources within the human body, including mechanical and biochemical energy to augment or even replace batteries. However, powering implantable nanodevices for biosensing using energy scavenging/harvesting technology is rather challenging because the only available energy in-vivo is mechanical, biochemical, and possibly electromagnetic energy, whereas thermal energy cannot be harvested due to lack of an adequate temperature gradient, and solar energy is not available for devices implanted inside the body.
Recent developments in harvesting mechanical energy by nanowire based nanogenerators (NG) has demonstrated an excellent route for harvesting the biomechanical energy created from tiny physical motion, such as the inhaling/exhaling of lungs or the beat of a heart. In addition, approaches have been demonstrated for converting the biochemical energy of glucose/O2 in biofluid using active enzymes as catalysts in a compartment-less biofuel cell (BFC).
Existing systems, however, usually harvest energy from a single available sources. This limits that amount of energy available for implantable devices.
Therefore, there is a need for an energy harvesting system that harvests energy more than one available source.